OP, I am guessing you tune your drums rather low? That wrinkle would come out at where I tune my drums.
Either way, a slight bend in a hoop or uneven bearing edge could create that crinkle. IF the drum sounds good to you, play on.
You need a room in a room. In your case a completely new ceiling below that ceiling and a floor above floor, and ideally all walls within the walls. As it stands vibration will also move up all your walls even though nobody on the other side.
Also, have you inquired if you are permitted to...